Barcode scanner buffer

Hello! I want to develop a Perspective application which have to read barcodes and store both scanned values and timestamp to a database. The scan will take place inside a bus and during its route, there are zones with no mobile service. I have tested the application with my phone and did 5-7 scans with no service (airplane mode) but only the 2 last scans are always forwarded to the gateway. Is any possibility to have a larger buffer? I'm using the perspective mobile application on an Android system to launch the project.
Thanks in advance for your advices!

See if this helps

Unrelated. The S&F system deals with breakage between the Gateway and the database. The OP is dealing with breakage between the mobile app and the gateway.

You are right Phil. It seems there is a buffer which stores only the 2 most recent scans. Hopefuly, there could be a way to increment this quantity.